Stable isotopes reveal opportunistic foraging in a spatiotemporally heterogeneous environment: Bird assemblages in mangrove forests
Fig 2
Cluster analysis showing bird species grouped by their blood δ13C and δ15N values at mangrove forest sites.
(A) Cocoa Creek and (B) Healy Creek. Symbols indicate each species’ foraging group as defined by the literature: omnivore (diamond), nectarivore-insectivore (square), carnivore (plus sign), and insectivore (open circle). Convex hulls delineate the three isotope-based foraging groups identified by cluster analysis at Cocoa Creek (C_1, C_2, C_3) and Healy Creek (H_1, H_2, H_3). The axes show standardized values of bird blood δ13C and δ15N values (mean = 0, standard deviation = 1).